1. Field of the Disclosure
The present invention relates to organic electro-luminescence display devices and a method for fabricating the same, and, more particularly, to an organic electro-luminescence display device and a method for fabricating the same, in which damage to a pad portion is prevented for improving yield.
2. Discussion of the Related Art
Recently, various kinds of flat display devices are under development for reducing weight and volume which is disadvantages of the cathode ray tube. In the flat display devices, there are liquid crystal display devices LCD, field emission display devices FED, plasma display panels PDP, electro-luminescence display devices by using organic electro-luminescence display devices (organic EL display device), and so on. Researches for improving a display quality and fabricating a large sized screen are undergoing, actively.
Of the flat display devices, the organic EL display device, a spontaneous emission device, has advantages of a fast response speed, high emission efficiency and luminance, and a large angle of view. The organic EL display device is provided with a thin film transistor array unit formed on a transparent substrate, an organic EL array unit on the thin film transistor array unit, and a glass cap for isolating the organic array unit from an external environment.
The thin film transistor array unit has gate lines, data lines, and driving units for driving organic EL cells, such as a cell driving units.
The organic EL array unit has a matrix of organic EL cells connected to driving thin film transistors in the thin film transistor array unit.
The organic EL cells in the organic EL array unit are susceptible to degradation by moisture and oxygen. In order to solve such problems, an encapsulation step is performed for protecting the organic EL array unit from external force and oxygen and moisture in the air.
In the meantime, recently, in order to make the organic EL display device thin or slim to minimize a volume of the organic EL display device, an etchant is sprayed to the lower substrate having the thin film transistor array unit formed thereon, thereby minimizing a thickness thereof. In this instance, even though the reduction of the thickness of the lower substrate by using the etchant enables to make the organic EL display device thin or slim, a problem is caused, in which a neighborhood of the pad portion connected to the thin film transistor array unit is broken.
In more detail, though the thickness becomes thin throughout the lower substrate if the thickness of the lower substrate is reduced by using the etching solution, as the thickness becomes thin, the lower substrate overlapped with the pad portion is broken in a chip on glass step, an FPC (Flexible Printed Circuit) step, or a modulizing step.